Question

我需要在两个地方之间使用路线服务谷歌地图进行指导。

代码工作正常，但我想在加载页面后直接向我显示方向而不在选择区域中进行选择

我试图在select中添加一个选项，但它不起作用

<select id="start">
<option value="chicago, il">Chicago</option>
</select>
<select id="end">
<option value="flagstaff, az">Flagstaff, AZ</option>
</select>

这是完整的代码 Code in google api

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<style>
#map {
height: 100%;
}
</style>
</head>
<body>
<div id="floating-panel">
<b>Start: </b>
<select id="start">
<option value="chicago, il">Chicago</option>
<option value="st louis, mo">St Louis</option>
<option value="joplin, mo">Joplin, MO</option>
</select>
<b>End: </b>
<select id="end">
<option value="oklahoma city, ok">Oklahoma City</option>
<option value="amarillo, tx">Amarillo</option>
<option value="gallup, nm">Gallup, NM</option>
</select>
</div>
<div id="map"></div>
<script>
function initMap() {
var directionsService = new google.maps.DirectionsService;
var directionsDisplay = new google.maps.DirectionsRenderer;
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 7,
center: {lat: 41.85, lng: -87.65}
});
directionsDisplay.setMap(map);

var onChangeHandler = function() {
calculateAndDisplayRoute(directionsService, directionsDisplay);
};
document.getElementById('start').addEventListener('change', onChangeHandler);
document.getElementById('end').addEventListener('change', onChangeHandler);
}

function calculateAndDisplayRoute(directionsService, directionsDisplay) {
directionsService.route({
origin: document.getElementById('start').value,
destination: document.getElementById('end').value,
travelMode: 'DRIVING'
}, function(response, status) {
if (status === 'OK') {
directionsDisplay.setDirections(response);
} else {
window.alert('Directions request failed due to ' + status);
}
});
}
</script>
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap">
</script>
</body>
</html>

Answer 1

如果我理解正确，您希望在select元素中设置默认值，并在页面加载时显示这些默认值之间的路径。在这种情况下，您应该在开始和结束选择框的选项中添加属性selected，并在calculateAndDisplayRoute(directionsService, directionsDisplay);函数的末尾调用initMap()。看一下下面的例子，它显示了页面加载时芝加哥和弗拉格斯塔夫之间的路线：

＆＃13;

function initMap() {
  var directionsService = new google.maps.DirectionsService;
  var directionsDisplay = new google.maps.DirectionsRenderer;
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 7,
    center: {lat: 41.85, lng: -87.65}
  });
  directionsDisplay.setMap(map);

  var onChangeHandler = function() {
    calculateAndDisplayRoute(directionsService, directionsDisplay);
  };
  document.getElementById('start').addEventListener('change', onChangeHandler);
  document.getElementById('end').addEventListener('change', onChangeHandler);
  
  calculateAndDisplayRoute(directionsService, directionsDisplay);
}

function calculateAndDisplayRoute(directionsService, directionsDisplay) {
  directionsService.route({
    origin: document.getElementById('start').value,
    destination: document.getElementById('end').value,
    travelMode: 'DRIVING'
  }, function(response, status) {
    if (status === 'OK') {
      directionsDisplay.setDirections(response);
    } else {
      window.alert('Directions request failed due to ' + status);
    }
  });
}

＆＃13;

#map {
  height: 100%;
}
html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}
#floating-panel {
  position: absolute;
  top: 10px;
  left: 25%;
  z-index: 5;
  background-color: #fff;
  padding: 5px;
  border: 1px solid #999;
  text-align: center;
  font-family: 'Roboto','sans-serif';
  line-height: 30px;
  padding-left: 10px;
}

＆＃13;

<div id="floating-panel">
<b>Start: </b>
<select id="start">
  <option value="chicago, il" selected>Chicago</option>
  <option value="st louis, mo">St Louis</option>
  <option value="joplin, mo">Joplin, MO</option>
  <option value="oklahoma city, ok">Oklahoma City</option>
  <option value="amarillo, tx">Amarillo</option>
  <option value="gallup, nm">Gallup, NM</option>
  <option value="flagstaff, az">Flagstaff, AZ</option>
  <option value="winona, az">Winona</option>
  <option value="kingman, az">Kingman</option>
  <option value="barstow, ca">Barstow</option>
  <option value="san bernardino, ca">San Bernardino</option>
  <option value="los angeles, ca">Los Angeles</option>
</select>
<b>End: </b>
<select id="end">
  <option value="chicago, il">Chicago</option>
  <option value="st louis, mo">St Louis</option>
  <option value="joplin, mo">Joplin, MO</option>
  <option value="oklahoma city, ok">Oklahoma City</option>
  <option value="amarillo, tx">Amarillo</option>
  <option value="gallup, nm">Gallup, NM</option>
  <option value="flagstaff, az" selected>Flagstaff, AZ</option>
  <option value="winona, az">Winona</option>
  <option value="kingman, az">Kingman</option>
  <option value="barstow, ca">Barstow</option>
  <option value="san bernardino, ca">San Bernardino</option>
  <option value="los angeles, ca">Los Angeles</option>
</select>
</div>
<div id="map"></div>
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyDztlrk_3CnzGHo7CFvLFqE_2bUKEq1JEU&callback=initMap">
</script>

＆＃13;

我希望这有帮助！

路线服务Google Maps API

1 个答案: